Dry Tortugas National Park

Dry Tortugas is one of the most remote and least visited national parks in America, a scatter of seven small islands and surrounding reef lying about 70 miles west of Key West, in the open Gulf waters at the far tip of Florida. Almost the entire park is ocean, and reaching it requires a proper sea journey by ferry or seaplane, which is precisely what makes arriving feel like a genuine expedition.

A fortress at the edge of the sea

Dominating the main island is Fort Jefferson, a colossal 19th-century brick fortress, one of the largest masonry structures in the Americas, rising improbably from the turquoise shallows. Never fully completed, it once guarded the shipping lanes and later served as a prison. Around it lie clear, warm waters, vibrant coral reefs and abundant marine life, while the islands are a crucial stopover for migrating birds and a nesting ground for sea turtles, which give the park its name. For a UK family, the combination of dramatic history and pristine, snorkel-ready waters is irresistible.

Dry Tortugas rewards the effort of getting there many times over. The journey itself, whether by fast ferry or low-flying seaplane over impossibly clear water, is part of the magic, and the first sight of Fort Jefferson floating on the horizon is unforgettable. Wandering the fort's vast brick ramparts, with the sea on every side, feels like stepping into an adventure story.

Then you slip into the water. The shallows around the fort are warm, calm and teeming with fish and coral, making this some of the most accessible and rewarding snorkelling anywhere in the national park system, ideal for teenagers. Add pristine sand, birdlife and a profound sense of being somewhere very few people ever reach, and you have a day out that feels both restful and genuinely exotic.

Once you land on Garden Key, the main island, getting around is entirely on foot, and the island is small enough to explore comfortably in a day. You walk the ramparts and passageways of Fort Jefferson, stroll the short stretches of beach, and wade or swim straight from the shore to snorkel the reefs and the historic moat wall. There are no roads, vehicles or shuttles anywhere in the park; the sea is the highway and your boat or seaplane is how you arrive and leave. The other islands are largely off-limits to protect wildlife. Plan your day around the ferry's fixed departure time, since missing it means being stranded, and make the most of the few hours ashore.

There is no conventional public transport to Dry Tortugas; the park is reached only by the licensed ferry or seaplane from Key West, and these function as your scheduled transport. To reach Key West itself, a family of five is best served by a hire car for the scenic drive down the Keys from Miami, giving flexibility and luggage space, though flying into Key West is an alternative. Once you commit to the day trip, the ferry or seaplane is the sole way across the water. Book those seats early, and treat the car as your means of reaching the departure point rather than the park itself.

• Book the ferry from Key West well in advance; daily capacity is strictly limited and it sells out, especially in high season.
• The ferry fare typically includes breakfast, lunch, snorkel gear and a fort tour, making it excellent value; check what is included.
• Bring everything you need for the day, as there are no shops or facilities beyond very basic ones on the island.
• The snorkelling around the fort's moat wall is superb and easy; don't leave without getting in the water.
• Apply reef-safe sun cream generously and wear a rash vest, as shade is scarce and the sun fierce.
• Seaplanes offer a spectacular but pricier alternative and reach the island faster.
• The sea can be choppy, so take precautions if anyone gets seasick.

Dry Tortugas has a warm, tropical marine climate. Winter and spring are the most comfortable, with pleasant temperatures, lower humidity and generally calmer seas, making them the prime time to visit. Summers are hot and humid with strong sun and a real chance of afternoon storms, and the wider region has a hurricane season later in the year. The water stays warm and inviting for much of the year. Pack light, quick-drying clothing, a rash vest, a hat, plenty of reef-safe sun cream and sunglasses, as shade on the island is minimal. Bring a light layer for the potentially breezy boat crossing.

Getting to Dry Tortugas is a two-part journey with a memorable sea leg at its heart. First you reach Key West, either by driving the famous Overseas Highway down the Florida Keys from Miami (a scenic three to four hours) or by a short flight into Key West (EYW). From Key West, the park is reached only by the daily passenger ferry, which takes a couple of hours each way across open water, or by a faster seaplane. There is no other way in. For a UK family, flying transatlantic into Miami, then working down the Keys and out to the Tortugas, makes a wonderful, self-contained adventure. Book your ferry or seaplane seats well ahead, as places are strictly limited and the crossing is the only route to the park.